Leo's Blog

Q:Given a non-empty array of integers, return the k most frequent elements.For example,Given [1,1,1,2,2,3] and k = 2, return [1,2].Note: You may assume k is always valid, 1 ≤ k

Q:Given an array of integers, every element appears twice except for one. Find that single one.思路:一个整数异或它本身,结果为0. 所以只要遍历一次数组即可得到只出现一次的数字.代码:public int singleNumber(int[] nums) { int le

Q:Given an array of strings, group anagrams together.For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return:[ ["ate", "eat","tea"], ["nat","tan"], ["bat"]]

Q:Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.思路:n个点,最多形成 (n-1)! 条线段,利用2个点p[i],p[j](j=i+1)可以得到它们所有的所属直线的斜率.以该斜率为key, Set为value,set中存放的是构成